I was curious about two field types for DCC...
First, it would be awesome if there is a "user" field type. What I've got in mind is that, in "read" mode, it would show some templated value like [DisplayName] ([Title]) or something (where we could change the template, of course). Then, in "edit" mode, it would be a type-to-search thing, like how messages works, allowing me to select a user. This would be huge for all sorts of things...
The next one I was wondering about is file uploads. In read mode, it could show a download link or icon or something... and in edit mode, let you upload a file of some type(s).
As a last thought, it would be very cool if we could do templated default values on fields. For example... say I wanted to use DCC to take applications for a program. It would be cool if I could make a field "Applicant" that is a user type, but that defaults to the user ID of the current user. Then, have a field like "Resume" that's a file upload.
Anyway - I know this is all still in development... but I'm really excited about the potential of DCC to really change a lot with DNN's core functionality... and I think including those things would be great.